Reconsider Snapshot Format

[mitsuhiko]

Currently stdout/stderr are just written in like this. There might be better ways:

[cnpryer]

FWIW I've been using insta working on ruff PRs. My experience is limited, but I think the way information is currently presented is fine. Not sure if you're looking for more strategic changes, but here are a couple things I've been curious of:

• Would it be better to have the file info at the bottom of each review section? I find myself scrolling up and down a lot.
• After a while you get pretty used to reading the results, but in the beginning things like this would make the ramp up a little difficult. I'd love to immediately ramp up with confidence in what I'm interpreting. Not sure how solvable this is from a display perspective.
• I kept pressing a in reviews accidentally selecting "accept". Idk if it's more that I forget I'm in review mode or if I'm not focused on the fact that I'm interacting with a list of options. Maybe use of the arrow keys could help? Idk if I have even tried that yet. lol

I haven't experienced testing like ruff's, but I really like it. Even though it can be a little tough to ramp up, it feels good to use it once you get the hang of it.

Now more strategic things that make command testing easier could be emphasizing on things like the actual experience of using the command. Rather than just "here's the expected result, did it change?", maybe there's opportunity to include "tests" for changes in experience with responsiveness, interface consistency, etc. I'm sure benchmarking is out of scope, but the time it takes for a command to run would be interesting to me.